Dark versus bright equilibrium hues: rod and cone biases

J Opt Soc Am A Opt Image Sci Vis. 2014 Apr 1;31(4):A75-81. doi: 10.1364/JOSAA.31.000A75.

Abstract

Equilibrium (unique) red, green, blue, and yellow stimuli look bright in a black surround, but they look dark in a bright white surround, and yellow changes to brown. We investigated differences in equilibrium-hue chromaticity between bright and dark hues to reveal changes in weighting of cone and rod signals. The largest, most consistent shifts were found between yellow and brown, with equilibrium-brown chromaticity shifted toward red compared to equilibrium yellow at both photopic and mesopic levels. Also, at mesopic levels, rod influence reversed for most observers from a green bias for yellow to a red bias for brown. Bright/dark differences for blue, green, and red were much smaller and/or less consistent. Thus, shifts of cone and rod hue biases between bright and dark hues are most prominent in L-M-cone pathways, especially those activated by yellow and brown stimuli.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiology
  • Cerebral Cortex / radiation effects
  • Color Perception / physiology*
  • Color Perception / radiation effects*
  • Darkness*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Retinal Cone Photoreceptor Cells / cytology*
  • Retinal Cone Photoreceptor Cells / radiation effects*
  • Retinal Rod Photoreceptor Cells / cytology*
  • Retinal Rod Photoreceptor Cells / radiation effects*
  • Young Adult